-LRB- CNN -RRB- -- The first time , it happened almost by accident .

Just hours after delivery , a baby born with HIV in Mississippi was given high doses of three antiretroviral drugs . More than three years later , doctors say the little girl has no evidence of the life-threatening disease in her blood , despite being off medication for nearly two years .

Now doctors say another child born with the virus appears to be free of HIV after receiving similar treatment . The case report was presented at the annual Conference on Retroviruses and Opportunistic Infections in Boston this week .

The girl was delivered at Miller Children 's Hospital in Long Beach , California , last summer to a mother with HIV who had not received antiretroviral drugs during pregnancy . Doctors gave the baby high doses of three drugs -- AZT , 3TC and Nevirapine -- four hours after birth . Eleven days later , the virus was undetectable in her body and remained undetectable eight months later .

The California baby is still on antiretroviral treatment , so it 's too soon to tell if the child is actually in remission .

`` Taking kids off antiretroviral therapy intentionally is not standard of care , '' said Dr. Deborah Persaud , a virologist with Johns Hopkins Children 's Center who has been involved in both cases . `` At this time , there is no plan to stop treatment . ''

While doctors around the world are trying to duplicate the Mississippi case , more research needs to be done before new standards are implemented for treating babies born with HIV .

`` This has to be done in a clinical trial setting , because really the only way we can prove that we 've accomplished remission in these cases is by taking them off treatment , and that 's not without risks , '' Persaud said during her presentation at the conference .

A clinical trial designed to test the effectiveness of early treatment on infants born to HIV-positive mothers is set to begin in the next couple of months , she said . Infants will be started on a combination of antiretroviral therapy within 48 hours of birth and followed `` for an extended period of time to determine if the virus can be eradicated from their bodies , '' according to the National Institutes of Health .

The results could be a game changer in the fight against AIDS .

Timeline : AIDS moments to remember

The Mississippi baby

The child in Mississippi was born to a mother who received no prenatal care and was not diagnosed as HIV-positive herself until just before delivery , according to a case report published in October in the New England Journal of Medicine .

Researchers : Toddler cured of HIV

`` We did n't have the opportunity to treat the mom during the pregnancy as we would like to be able to do , to prevent transmission to the baby , '' said Dr. Hannah Gay , a pediatric HIV specialist at the University of Mississippi Medical Center .

Doctors administered the antiretroviral drugs 30 hours after the girl was born in hopes of controlling the virus . Within a couple of days , Gay confirmed the child was HIV-positive . She said the baby had probably been infected in the womb . The child remained on antiretroviral drugs for approximately 15 months . Her mother then stopped administering the drug for some reason , Gay said .

In March 2013 , researchers announced that the girl was the first child to be `` functionally cured '' of HIV . A `` functional cure '' is when the presence of the virus is so small , lifelong treatment is not necessary and standard clinical tests can not detect the virus in the blood .

Gay told CNN the timing of intervention -- before the baby 's HIV diagnosis -- may deserve `` more emphasis than the particular drugs or number of drugs used . ''

The researchers believe `` the very early therapy is blocking the spread of HIV into viral reservoirs that hold the virus for a lifetime , '' Persaud explained .

High-risk exposure

Researchers have long known that treating HIV-positive mothers early on is important , because they pass antibodies on to their babies .

All HIV-positive moms will pass on those antibodies , but only 30 % will transmit the actual virus , said Dr. Katherine Luzuriaga , an immunologist at the University of Massachusetts who worked closely with Gay . And HIV-positive mothers who are given appropriate treatment pass on the virus in less than 2 % of cases .

`` So all babies are born antibody-positive , but only a fraction of babies born to HIV-positive women will actually get the virus , and that fraction depends on whether the mom and baby are getting antiviral prophylaxis -LRB- preventive treatment -RRB- or not . ''

Newborns are considered high-risk if their mothers ' HIV infections are not under control or if the mothers are found to be HIV-positive when they 're close to delivering .

Usually , these infants would get antiviral drugs at preventive doses for six weeks to prevent infection , then start antiretroviral therapy , or ART , if HIV is diagnosed .

ART is a combination of at least three drugs used to suppress the virus and stop the progression of the disease .

But they do not kill the virus . Tests showed the virus in the Mississippi baby 's blood continued to decrease and reached undetectable levels within 29 days of the initial treatment .

HIV may be ` functionally cured ' in some

The ` Berlin patient '

Researchers say the only other documented case of an HIV cure is that of Timothy Brown , known as the `` Berlin patient . '' In 2007 , Brown , an HIV-positive American living in Germany , was battling both leukemia and HIV when he underwent a bone marrow transplant that cured not only his cancer but his HIV .

In an interview last year , Brown told Dr. Sanjay Gupta , CNN 's chief medical correspondent , that he was still HIV-free .

`` I 've been tested everywhere possible , '' said Brown , who now lives in San Francisco . `` My blood 's been tested by many , many agencies . I 've had two colonoscopies to test to see if they could find HIV in my colon , and they have n't been able to find any . ''

But Brown 's case is apparently unique .

And the procedure , which is extremely dangerous , wo n't work in most patients because the bone marrow he received had a special genetic mutation that made the stem cells in it naturally resistant to the virus .

Researchers tell CNN only 1 % of Caucasians -- mostly Northern Europeans -- and no African-Americans or Asians have this particular mutation .

In June , five years after he was `` cured , '' reports surfaced that `` traces '' of the virus had been found in Brown 's blood .

Even then , some HIV experts said that does n't matter , that he 's been cured . In fact , many AIDS experts said they believe Brown has experienced what 's called a `` sterilizing '' cure , meaning the virus has been eliminated from the body entirely .

In July , Boston researchers said two HIV patients showed no sign of the virus in their blood following bone marrow transplants . However , researcher Dr. Timothy Henrich said in December that the virus had returned .

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Baby born with HIV in California appears to be free of the virus

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She was given high doses of three antiretroviral drugs shortly after birth

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Case is similar to Mississippi baby `` functionally cured '' of HIV

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A clinical trial designed to test effectiveness of this treatment is starting soon